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RE-Molecular, Biochemical and Genetic Characteristics of BSE in Canada

Posted by flounder
on
19 May 2010 at 21:21 GMT

Greetings,

>>> The occurrence of atypical cases of BSE in countries such as Canada with low BSE prevalence and transmission risk argues for the occurrence of sporadic forms of BSE worldwide. <<<

In my opinion ;

THE statement above is about as non-scientific as a statement can be. There is no proof what-so-ever that any of the atypical BSE cases or atypical scrapie cases anywhere on the globe was a spontaneous case without any route and source of the TSE agent. This is a myth. The USDA and the OIE are trying to make the atypical BSE cases and they have already made the atypical Scrapie cases a legal trading commodity, without any transmission studies first confirming that in fact these atypical TSE will not transmit via feed. I suppose it is a human transmission study in progress. IT's like what happened in England with c-BSE and the transmission to humans via nvCJD never happened to the OIE and the USDA. Canada does not have a low prevalence of BSE either, they have a high prevalence. WHO knows about North America ? it's just that the U.S.A. try's much harder at concealing cases of mad cow disease. THIS was proven with the first stumbling and staggering mad cow in Texas, that was Wisk away to be rendered without any test at all. Then, you had the second case of mad cow disease that the USDA et al was almost as successful with as the first one, but the O.I.G. stepped in and demanded testing over seas, this after many scientist around the globe spoke out. Finally, after an act of Congress, the second case of mad cow disease in Texas was confirmed. all this was done for a reason, and that reason was the OIE USDA BSE MRR policy. Again, This study reeks of TRADE policy wrangling. There is NO proof that the atypical TSE are spontaneous. please show me these transmission studies ? on the other hand, we now know that the L-type atypical BSE is much more virulent than the typical C-BSE, and we now know that the H-type atypical BSE will transmit to humans. WHY can it not be that these atypical cases are simply from feed that had different strains of TSE ? WHY is it that no one will comment on the studies that was suppose to show infectivity of tissues from atypical BSE ? WHY is it I had to file a FOIA on that issue? L-type atypical BSE (BASE) is more virulent than classical BSE, has a lymphotropic phenotype, and displays a modest transmission barrier in our humanized mice. BSE-H is also transmissible in our humanized Tg mice. SEE Liuting Qing1, Wenquan Zou1, Cristina Casalone2, Martin Groschup3, Miroslaw Polak4, Maria Caramelli2, Pierluigi Gambetti1, Juergen Richt5, Qingzhong Kong1 et al 2009 ;

Atypical BSE, BSE, and other human and animal TSE in North America Update October 19, 2009

IS the h-BSE more virulent than typical BSE as well, or the same as cBSE, or less virulent than cBSE? just curious.....

Professor Kong reply ;

.....snip

As to the H-BSE, we do not have sufficient data to say one way or another, but we have found that H-BSE can infect humans. I hope we could publish these data once the study is complete. Thanks for your interest.

Background: Classical BSE is a world-wide prion disease in cattle, and the classical BSE strain (BSE-C) has led to over 200 cases of clinical human infection (variant CJD). Atypical BSE cases have been discovered in three continents since 2004; they include the L-type (also named BASE), the H-type, and the first reported case of naturally occurring BSE with mutated bovine PRNP (termed BSE-M). The public health risks posed by atypical BSE were argely undefined.

Objectives: To investigate these atypical BSE types in terms of their transmissibility and phenotypes in humanized mice.

Methods: Transgenic mice expressing human PrP were inoculated with several classical (C-type) and atypical (L-, H-, or Mtype) BSE isolates, and the transmission rate, incubation time, characteristics and distribution of PrPSc, symptoms, and histopathology were or will be examined and compared.

Results: Sixty percent of BASE-inoculated humanized mice became infected with minimal spongiosis and an average incubation time of 20-22 months, whereas only one of the C-type BSE-inoculated mice developed prion disease after more than 2 years. Protease-resistant PrPSc in BASE-infected humanized Tg mouse brains was biochemically different from bovine BASE or sCJD. PrPSc was also detected in the spleen of 22% of BASE-infected humanized mice, but not in those infected with sCJD. Secondary transmission of BASE in the humanized mice led to a small reduction in incubation time. The atypical BSE-H strain is also transmissible with distinct phenotypes in the humanized mice, but no BSE-M transmission has been observed so far.

Discussion: Our results demonstrate that BASE is more virulent than classical BSE, has a lymphotropic phenotype, and displays a modest transmission barrier in our humanized mice. BSE-H is also transmissible in our humanized Tg mice. The possibility of more than two atypical BSE strains will be discussed.

Background: After the detection of two novel BSE forms designated H-type and L-type atypical BSE the question of the pathogenesis and the agent distribution of these two types in cattle was fully open. From initial studies of the brain pathology, it was already known that the anatomical distribution of L-type BSE differs from that of the classical type where the obex region in the brainstem always displays the highest PrPSc concentrations. In contrast in L-type BSE cases, the thalamus and frontal cortex regions showed the highest levels of the pathological prion protein, while the obex region was only weakly involved.

Methods:We performed intracranial inoculations of cattle (five and six per group) using 10%brainstemhomogenates of the two German H- and L-type atypical BSE isolates. The animals were inoculated under narcosis and then kept in a free-ranging stable under appropriate biosafety conditions. At least one animal per group was killed and sectioned in the preclinical stage and the remaining animals were kept until they developed clinical symptoms. The animals were examined for behavioural changes every four weeks throughout the experiment following a protocol that had been established during earlier BSE pathogenesis studies with classical BSE.

Results and Discussion: All animals of both groups developed clinical symptoms and had to be euthanized within 16 months. The clinical picture differed from that of classical BSE, as the earliest signs of illness were loss of body weight and depression. However, the animals later developed hind limb ataxia and hyperesthesia predominantly and the head. Analysis of brain samples from these animals confirmed the BSE infection and the atypical Western blot profile was maintained in all animals. Samples from these animals are now being examined in order to be able to describe the pathoge esis and agent distribution for these novel BSE types.

Conclusions: A pilot study using a commercially avaialble BSE rapid test ELISA revealed an essential restriction of PrPSc to the central nervous system for both atypical BSE forms. A much more detailed analysis for PrPSc and infectivity is still ongoing.

Background: An update on atypical BSE and other TSE in North America. Please remember, the typical U.K. c-BSE, the atypical l-BSE (BASE), and h-BSE have all been documented in North America, along with the typical scrapie's, and atypical Nor-98 Scrapie, and to date, 2 different strains of CWD, and also TME. All these TSE in different species have been rendered and fed to food producing animals for humans and animals in North America (TSE in cats and dogs ?), and that the trading of these TSEs via animals and products via the USA and Canada has been immense over the years, decades.

Methods: 12 years independent research of available data

Results: I propose that the current diagnostic criteria for human TSEs only enhances and helps the spreading of human TSE from the continued belief of the UKBSEnvCJD only theory in 2009. With all the science to date refuting it, to continue to validate this old myth, will only spread this TSE agent through a multitude of potential routes and sources i.e. consumption, medical i.e., surgical, blood, dental, endoscopy, optical, nutritional supplements, cosmetics etc.

Conclusion: I would like to submit a review of past CJD surveillance in the USA, and the urgent need to make all human TSE in the USA a reportable disease, in every state, of every age group, and to make this mandatory immediately without further delay. The ramifications of not doing so will only allow this agent to spread further in the medical, dental, surgical arena's. Restricting the reporting of CJD and or any human TSE is NOT scientific. Iatrogenic CJD knows NO age group, TSE knows no boundaries. I propose as with Aguzzi, Asante, Collinge, Caughey, Deslys, Dormont, Gibbs, Gajdusek, Ironside, Manuelidis, Marsh, et al and many more, that the world of TSE Transmissible Spongiform Encephalopathy is far from an exact science, but there is enough proven science to date that this myth should be put to rest once and for all, and that we move forward with a new classification for human and animal TSE that would properly identify the infected species, the source species, and then the route.

To date the OIE/WAHO assumes that the human and animal health standards set out in the BSE chapter for classical BSE (C-Type) applies to all forms of BSE which include the H-type and L-type atypical forms. This assumption is scientifically not completely justified and accumulating evidence suggests that this may in fact not be the case. Molecular characterization and the spatial distribution pattern of histopathologic lesions and immunohistochemistry (IHC) signals are used to identify and characterize atypical BSE. Both the L-t pe and H-type atypical cases display significant differences in the conformation and spatial accumulation of the disease associated prion protein (PrPSc) in brains of afflicted cattle. Transmission studies in bovine transgenic and wild type mouse models support that the atypical BSE types might be unique strains because they have different incubation times and lesion profiles when compared to C-type BSE. When L-type BSE was inoculated into ovine transgenic mice and Syrian hamster the resulting molecular fingerprint had changed, either in the first or a subsequent passage, from L-type into C-type BSE. In addition, non-human primates are specifically susceptible for atypical BSE as demonstrated by an approximately 50% shortened incubation time for L-type BSE as compared to C-type. Considering the current scientific information available, it cannot be assumed that these different BSE types pose the same human health risks as C-type BSE or that these risks are mitigated by the same protective measures.

IN FACT, the fumbling and bumbling the USDA and FDA et al did with the infamous 2004 enhanced BSE surveillance program was so BAD, one of the leading scientist for the NIH/CDC et al on prions, Dr. Paul Brown was quoted as saying ;

"The fact the Texas cow showed up fairly clearly implied the existence of other undetected cases," Dr. Paul Brown, former medical director of the National Institutes of Health's Laboratory for Central Nervous System Studies and an expert on mad cow-like diseases, told United Press International. "The question was, 'How many?' and we still can't answer that." Brown, who is preparing a scientific paper based on the latest two mad cow cases to estimate the maximum number of infected cows that occurred in the United States, said he has "absolutely no confidence in USDA tests before one year ago" because of the agency's reluctance to retest the Texas cow that initially tested positive. USDA officials finally retested the cow and confirmed it was infected seven months later, but only at the insistence of the agency's inspector general. "Everything they did on the Texas cow makes everything USDA did before 2005 suspect," Brown said. ...